Method for hot dip galvanizing torsion bar suspension systems for trailer wheels

ABSTRACT

A method and means of hot dip galvanizing completely assembled and machined trailer wheel suspension systems as a unit, without affecting machined wheel spindle surfaces, is described. Spindle protective sleeve caps having an interior nut operative to be screw-threaded on the wheel retainer nut threading at the outer end of a wheel spindle enables force-fitting the inner end of the sleeve cap in sealing relation against the suspension arm hub which carries the spindle, so as to completely cover and seal the spindle during unitary hot dip galvanizing of the suspension system.

United States Patent [1 1 Whitley, Jr.

[ Nov. 13, 1973 [76] Inventor: William P. Whitley, Jr., 4525 E.

10th Ln., Hialeah, Fla. 33103 [22] Filed: Mar. 8, 1972 [21] Appl. No.:232,677

[52] US. Cl 117/48, 117/114 A, 118/505 [51] Int. Cl. C23c l/02 [58]Field of Search 117/48,114 A, 114 B, 117/114 C, 114 R; 118/504, 505,DIG. 12

[56] References Cited UNITED STATES PATENTS 690,039 12/1901 Smith118/505 1,184,315 5/1916 Buch r 117/94 3,393,597 7/1968 Hoaglund....118/505 X 3,535,136 10/1970 Beene 118/504 X 727,010 5/1903 Smith 118/505947,544 l/l9l0 Haeske 118/505 1,159,820 11/1915 Armstrong 117/48 X3,226,245 12/1965 Dettling et a1. 118/505 X 3,667,988 6/1972 Horiki117/48 X Primary Examiner-Ralph S. Kendall Attorney-Ernest H. Schmidt[57] ABSTRACT A method and means of hot dip galvanizing completelyassembled and machined trailer wheel suspension systems as a unit,without affecting machined wheel spindle surfaces, is described. Spindleprotective sleeve caps having an interior nut operative to bescrew-threaded on the wheel retainer nut threading at the outer end of awheel spindle enables force-fitting the inner end of the sleeve cap insealing relation against the suspension arm hub which carries thespindle, so as to completely cover and seal the spindle during unitaryhot dip galvanizing of the suspension systern.

4 Claims, 3 Drawing Figures METHOD FOR HOT DIP GALVANIZING TORSION BARSUSPENSION SYSTEMS FOR TRAILER WHEELS This invention relates to wheelsuspensions for trailers and is directed particularly to a method andmeans for hot dip galvanizing such suspension system assemblies as aunit without at the same time galvanizing or otherwise affecting themachine-finish surfaces of the wheel spindles thereof.

In my Pat. application, Ser. No. 174,365, filed Aug. 24, 1971, issuedMar. 27, 1973 as US. Pat. No. 3,722,908 I describe a torsion barsuspension for tandem wheels for boat trailers and the like and which isparticularly well adapted to use with low-slung trailer carriage framessuitable for positioning partially submerged in shallow water with themain trailer boat support surfaces under the water to permit a traileredboat to be floated off the trailer.

Partially submersible trailers having low-slung carriage frames andadaptable to float-on and float-off loading and unloading of a traileredboat have heretofore been devised. Such wheel suspension systemsheretofore known, however, notwithstanding elaborate counter-measures,such as painting with rust preventives or the like, have been found tobe subject of ex-' tensive rusting or corrosion after only a few seasonsuse, especially when used in salt water. The rusting and corrosion notonly results in an unsightly appearance of the suspension system butalso can weaken it to such an extent as to cause impaired spring actionand even complete breakdown.

Attempts at hot dip galvanizing completed wheel suspension assemblies toprevent rusting and corrosion have been unsuccessful because removal ofthe galvanization coating from the spindles to restore themachine-finished surfaces proved to be a difficult and expensiveprocedure. Attempts at assembling wheel spindles to the remainder of thesuspension system after its galvanization, moreover, were found to bedeficient in that they necessitated re-machining after assembly to theremainder of the suspension assembly.

It is accordingly the principal object of this invention to provide anovel and improved method and means for hot dip galvanizing wheelsuspension assemblies as a unit and thereby afford complete protectionagainst rusting and significant corrosion without in any way affectingthe prefinished machined surfaces of the wheel spindles.

It is another object of this invention to provide a method and means foreffectively covering the machine-finished spindles of wheel suspensionassemblies with a reusable sleeve cap to permit hot dip galvanizing ofthe suspension assembly as a unit without in any way affecting theprefinished machined surfaces of the spindles.

It is a more particular object of the invention to provide a wheelspindle protective cap of the character describedthat fits telescopinglyover a wheel spindle and includes internal nut means for screwing uponthe threaded end of a spindle to permit force-fitting the inner end ofthe sleeve cap against a sealing packing placed therebetween and anannular shoulder portion of the spindle.

Yet another object of the invention is to provide a method and means ofhot dip galvanizing completed wheel suspension assemblies which will besimple in operation, economical in manufacture and efficient anddependable in operation.

Other objects, features and advantages of the invention will be apparentfrom the following description when read with reference to theaccompanying drawings. In the drawings, wherein like reference numeralsdenote corresponding parts throughout the several views:

FIG. 1 illustrates, in plain view, a torsion bar suspension system fortandem wheels equipped with protective spindle caps embodying theinvention in preparation for hot dip galvanizing;

FIG. 2 is a side view of the suspension system illustrated in FIG. 1;and

FIG. 3 is a longitudinal cross-sectional view, taken along the line 33of FIG. 1, on an enlarged scale, illustrating constructional details ofthe protective spindle cap and the wheel spindle to which it isassembled.

Referring now in detail to the drawings, reference numeral 10 in FIGS. 1and 2 designates a torsion bar suspension system for tandem trailerwheels, the spindles ll of which are fitted with spindle protectivesleeve caps 12 comprising the invention. Since the torsion barsuspension system 10 is described in detail in my United States patentreferred to above, a detailed description is not deemed necessary hereinfor a full understanding of the present invention. In brief, it will beunderstood that the suspension system comprises a metal supportingframework 13 adapted to be secured to the undercarriage of a trailer,which supporting framework has, longitudinally fitted and securedtherein, a pair of spaced, parallel torsion bars 14, 15, the outwardlyprojecting ends of which carry, respectively, laterally-opposed momentarm members 16, 16 and 17, 17. The outer ends of the moment arms l6, l6and 17, 17 are formed with hub portions 18, each of which is providedwith a spindle 11. It is further to be understood that assembly 10 willbe appropriately jigged and bored to receive, press-fitted therein themachine finished spindles for proper wheel suspension when fitted to atrailer carriage frame. Upon galvanization, the inner ends of thespindles will be galvanizewelded to their respective moment arm members.

As best illustrated in FIG. 3, the protective sleeve caps 12 eachcomprise a tubular sleeve portion 19, one end of which is provided witha coaxial, internally threaded blind bore or nut portion 20 threadinglyreceivable on the externally threaded outer end 21 of a wheel spindle l1, said spindle thread being the ordinary threading provided forreception of the wheel-retainer nut upon subsequent assembly of thewheels to the suspension system. The outer or nut end of the sleeveportion 19 is further provided with an outwardly extending, solid,hexagonal lug'portion 22 for co-operative fitting thereto of an impactwrench, as is hereinafter described. The inner end of the protective capsleeve portion 19 is internally countersunk to provide an in-'creased-diameter interior, annular wall portion 23 terminating in aninwardly inclined chamfer 24. The protective sleeve cap 12 canconveniently be fabricated either of solid steel stock, or assembled ofappropriate lengths of steel tubing and hexagonal bar stock, weldedtogether and internally bored; threaded and chamferred.

As further illustrated 'in FIG. 3, each of the wheel spindles 11 isformed with a cylindrical body support portion 25 of such diameter as tobe press-fitted within a central, through bore 26 in its moment arm hubportion 18, whereat it is secured permanently in place, such as by meansof a peripheral weld 27 at the outer end of said body support portion.The outwardly projecting portion of the spindle 11 is formed with afirst reduced-diameter portion 28 defining an annular shoulder 29. Thefirst reduced-diameter portion 28 extends into a still further reducedcylindrical portion 30 for reception of an inner wheel bearing anddefining, with said first reduced-diameter portion, an annular shoulder31. The annular shoulder 31 provides a slide surface for a grease sealring fitted in place upon subsequent assembly of a trailer wheel to thespindle. The wheel spindle reduced-diameter cylindrical portion 30extends into a third reduced-diameter portion 32 which, in turn, extendsinto a fourth reduced-diameter outer wheel bearing portion 33. The outerwheel bearing portion 33 terminates in the still further reduced,externally threaded wheel spindle outer end 21.

In use, a protective sieeve cap 12, as illustrated in FIG. 3, will betelescopingly fitted over a machinefinished wheel spindle andscrew-threaded on the externally threaded outer end 21 thereof. Theinternal diameter of the annular wall portion 23 at the inner end of theprotective sleeve cap 12 is such as to slide fit in embracing relationalong the first reduced-diameter 28 of said spindle. The hexagonal lugportion 22 at the outer end of the protective sleeve cap 12 serves to beengaged by a power-driven impact wrench for driving said sleeve cap homeagainst the annular shoulder 29 at the inner end of the wheel spindle11.

To ensure heat resistant sealing action at the abutment zone, theannular recess defined by the chamfer 24 at the inner end of theprotective sleeve cap 12 is packed with a packing of graphited asbestosjust prior to power driving said sleeve cap home. After all of the wheelspindles of a prefabricated suspension system have thus been fitted withprotective sleeve caps 12, the assembly is ready for hot dip galvanizingin molten zinc at a temperature of about 800 F.

It is to be noted that despite the very high temperature to which theentrapped air within the protective sleeve caps 12 is subjected duringthe galvanizing process, the volumes of such entrapped air are so smallas to keep pressures resulting from their expansion within safe limits.

After completion of the galvanizing process, the protective sleeve caps12 can readily be removed, by use of a power-driven impact wrench, forsubsequent reuse. Any galvanization coating between moving parts of thesuspension system, such as the flexure zones between the inner ends ofthe moment arm members 16, 16; l7, l7 and outer end portions of thesupporting framework 14, will readily be broken by normal movement ofsaid moment arms with respect to said supporting framework. Since therewill be intermittent sliding frictional contact at these zones duringuse of the trailer to which the suspension system 10 is subsequentlyassembled, rusting and corroding cannot take the place at theseungalvanized zones.

Upon assembly of the trailer wheels to the suspension spindles, greaseseal rings in sliding contact with the annular shoulders 31 of eachspindle, together with grease caps fitted to the outsides of the wheelhubs, prevents the escape of wheel bearing grease, while at the sametime sealing against the entrance of water. The completely assembled,wheeled suspension system has thus been afforded complete protectionagainst water damage, whether due to rusting or corrosion or acombination of both, and is therefore particularly well suited forlong-wearing, dependable and maintenance free use in submersible typeboat trailers.

While I have illustrated and described herein only one form in which myinvention can conveniently be embodied in practice, it is to beunderstood that this form is given by way of example only and not in alimiting sense. The invention, in brief, comprises all the embodimentsand modifications coming within the scope and spirit of the followingclaims.

What I claim as new and desire to secure by Letters Patent is:

1. The method of hot dip galvanizing suspension system for trailerwheels having wheel spindles machinefinished with annular shoulders attheir inner ends and wheel retainer nut threading at their outer ends,comprising the steps of fitting a heat resistant packing membercircumjacent each spindle at its shoulder, then screw-threading aninternally tapped protective sleeve member over each spindle so that itsinner end is clamped against its respective packing member and spindleshoulder, then hot dip galvanizing the suspension system thus fittedwith protective sleeve caps, and finally removing said sleeve caps fromtheir respective spindles.

2. The method of hot dip galvanizing suspension systems for trailerwheels as defined in claim 1 wherein said heat resistant packing membersare of graphited asbestos.

3. The method of hot dip galvanizing suspension systems for trailerwheels as defined in claim 1 wherein the interior inner end of eachsleeve member is formed with an inwardly inclined chamber for securelywedging their respective packing members in place.

4. The method of hot dip galvanizing suspension systems for trailerwheels as defined in claim 3 wherein said heat resistant packing membersare of graphited asbestos.

* k i i t

2. The method of hot dip galvanizing suspension systems for trailerwheels as defined in claim 1 wherein said heat resistant packing membersare of graphited asbestos.
 3. The method of hot dip galvanizingsuspension systems for trailer wheels as defined in claim 1 wherein theinterior inner end of each sleeve member is formed with an inwardlyinclined chamber for securely wedging their respective packing membersin place.
 4. The method of hot dip galvanizing suspension systems fortrailer wheels as defined in claim 3 wherein said heat resistant packingmembers are of graphited asbestos.